SB2026051950 - Ubuntu update for linux

Description

This security bulletin contains information about 3 vulnerabilities.

1) Use-after-free (CVE-ID: CVE-2026-23209)

CWE-ID: CWE-416 - Use After Free

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a use-after-free error within the macvlan_common_newlink() function in drivers/net/macvlan.c. A local user can escalate privileges on the system.

2) Input validation error (CVE-ID: CVE-2026-23112)

CWE-ID: CWE-20 - Improper input validation

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to improper input validation within the nvmet_tcp_free_cmd_buffers() function in drivers/nvme/target/tcp.c. A local user can perform a denial of service (DoS) attack.

3) Improper locking (CVE-ID: CVE-2024-50304)

CWE-ID: CWE-667 - Improper Locking

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to improper locking within the ip_tunnel_find() function in net/ipv4/ip_tunnel.c. A local user can perform a denial of service (DoS) attack.

Remediation

Install update from vendor's website.

References

• https://ubuntu.com/security/notices/USN-8273-1